METHOD AND APPARATUS FOR DYNAMIC LMA ASSIGNMENT IN PROXY MOBILE IPv6 PROTOCOL

ABSTRACT

Methods and apparatuses are provided for supporting mobility in a Proxy Mobile Internet Protocol (“IP”) network without having a mobile node (“MN”) to participate in certain mobility related signaling. Instead, a proxy agent might implement functions of a mobile access gateway (“MAG”) in a Proxy Mobile Internet Protocol Version 6 (“IPv6”) network. The proxy agent, rather than the MN, might send a request to a Dynamic Host Configuration Protocol (“DHCP”) server, and receive back a local mobility anchor address (“LMAA”) of a local mobility anchor (“LMA”). The proxy agent might instead perform a Domain Name System (“DNS”) lookup for the LMAA of the LMA first; in response to a failure to receive the LMAA, the proxy agent might then send the request to the DHCP server to receive the LMAA. The proxy agent might further update DNS information of the MN.

CROSS-REFERENCES TO RELATED APPLICATIONS

The present application claims benefit of U.S. provisional applicationNo. 60/946,719, filed on Jun. 27, 2007, entitled “SYSTEM FOR FASTHANDOVERS, AUTHENTICATION, AND FIREWALL TRAVERSAL FOR MOBILE IPv6NETWORKS,” the content of which is incorporated herein by reference forall purposes.

BACKGROUND

This application relates generally to communication in mobile networks.More specifically, this application relates to methods and apparatusesfor supporting mobility without having a mobile node to participate incertain mobility related signaling.

The ability to provide network access as a mobile device moves acrossnetworks or segments of a network is becoming more and more important.Emerging technologies including WiMAX promise to bring forth evengreater needs in providing users with transparent and seamless access toInternet Protocol (“IP”) networks including the Internet. The Mobile IPprotocol is designed to meet some of these needs, and Mobile IPv6 is aversion of Mobile IP.

The Mobile IPv6 protocol has been extended to support IP mobilitywithout having a mobile device to participate in certain mobilityrelated signaling. More specifically, the Proxy Mobile IPv6 protocol hasbeen proposed for providing NETwork based, Localized Mobility Management(“NETLMM”). In a Proxy Mobile IPv6 network, proxy agents based in thenetwork are responsible for managing IP mobility on behalf of the mobiledevice.

To support IP mobility more fully without having a mobile device toparticipate in certain mobility related signaling, there is a generalneed to improve the proxy agents and their capabilities.

BRIEF SUMMARY

Embodiments of the invention provide methods and apparatuses forsupporting mobility without having a mobile node (“MN”) to participatein certain mobility related signaling. In one set of embodiments, ratherthan having a MN to discover an address of the MN's home agent, theaddress of the MN's home agent is dynamically assigned. Morespecifically, a proxy agent is responsible to discover the address ofthe MN's home agent on behalf of the MN. In a Proxy Mobile InternetProtocol Version 6 (“IPv6”) network, the MN's home agent might implementfunctions of a local mobility anchor (“LMA”), and the proxy agent mightimplement functions of a mobile access gateway (“MAG”).

In some embodiments, the MAG might discover the address of the MN's LMAby sending a request to a Dynamic Host Configuration Protocol (“DHCP”)server. In other embodiments, the MAG might discover the address of theMN's LMA by performing a Domain Name System (“DNS”) lookup of FullyQualified Domain Name (“FQDN”) information of the LMA. In yet otherembodiments, the MAG might send the request to the DHCP server inresponse to a failure to receive the address of the MN's LMA afterperforming the DNS lookup.

In another set of embodiments, after an address of the MN has beenconfigured, rather than having the MN to update DNS information of theMN, the DNS information of the MN is updated by the MAG. In someembodiments, the address of the MN might be configured after the MAG hasreceived prefix information for the MN from the MN's LMA; the address ofthe MN's LMA might have been discovered earlier by the MAG

Accordingly, the MN no longer participates in certain mobility relatedsignaling. Rather, the certain mobility related signaling is performedby the improved MAG based in the network. Consequently, fewer burdensare placed on the MN and communication needs of the MN are alsolessened, both leading to improved network access for mobile devices.

In one embodiment, a method for managing communication in a mobilenetwork might include sending a request for a local mobility anchoraddress (“LMAA”) of a local mobility anchor (“LMA”) from a mobile accessgateway (“MAG”) in a Proxy Mobile Internet Protocol Version 6 (“IPv6”)network to a Dynamic Host Configuration Protocol (“DHCP”) server. Themethod might also include receiving the LMAA of the LMA from the DHCPserver.

In another embodiment, a method for managing communication in a mobilenetwork might include receiving Fully Qualified Domain Name (“FQDN”)information of a local mobility anchor (“LMA”) from an Authentication,Authorization and Accounting (“AAA”) server at a mobile access gateway(“MAG”) in a Proxy Mobile Internet Protocol Version 6 (“IPv6”) network.The method might also include performing a Domain Name System (“DNS”)lookup of the FQDN information of the LMA for a local mobility anchoraddress (“LMAA”) of the LMA.

In yet another embodiment, a method for managing communication in amobile network might include sending a Domain Name System (“DNS”) updaterequest message from a mobile access gateway (“MAG”) in a Proxy MobileInternet Protocol Version 6 (“IPv6”) network to an Authentication,Authorization and Accounting (“AAA”) server, wherein the DNS updaterequest message includes Fully Qualified Domain Name (“FQDN”)information of the MN. The method might also include receiving a replymessage from the AAA server, wherein the reply message includes a resultof updating the FQDN information of the MN.

The methods of the invention may be embodied in an apparatus comprisingcircuitry for operating the apparatus in accordance with the embodimentsdescribed above. The methods of the invention may also be embodied in anapparatus comprising a communication interface, a storage medium, acontroller, and a set of instructions executable by the controller foroperating the apparatus in accordance with the embodiments describedabove. Moreover, the methods of the invention may be embodied in acomputer-readable storage medium having a computer-readable programembodied therein for directing operations of an apparatus including acontroller. The computer-readable program includes instructions foroperating the apparatus in accordance with the embodiments describedabove.

BRIEF DESCRIPTION OF THE DRAWINGS

A further understanding of the nature and advantages of particularembodiments may be realized by reference to the following drawings. Inthe drawings, like reference labels are used throughout the severaldrawings to refer to similar components. In some instances, a sublabelis associated with a reference numeral followed by a hyphen to denoteone of multiple similar components. When reference is made to areference numeral without specification to an existing sublabel, it isintended to refer to all such multiple similar components.

FIG. 1A provides a high level diagram illustrating a Proxy Mobile IPv6network in an embodiment of the invention.

FIG. 1B provides a schematic diagram illustrating a Proxy Mobile IPv6network in an embodiment of the invention.

FIG. 2 is a flow diagram illustrating methods for supporting mobilitywithout having a mobile node to participate in certain mobility relatedsignaling in an embodiment of the invention.

FIG. 3 is a flow diagram summarizing methods for supporting mobilitywithout having a mobile node to participate in certain mobility relatedsignaling in an embodiment of the invention.

DETAILED DESCRIPTION

Embodiments of the invention provide methods and apparatuses forsupporting mobility without having a mobile node (“MN”) to participatein certain mobility related signaling. Merely by way of example, in oneembodiment, a proxy agent might implement functions of a mobile accessgateway (“MAG”) in a Proxy Mobile Internet Protocol Version 6 (“IPv6”)network. The MAG, rather than the MN, might send a request to a DynamicHost Configuration Protocol (“DHCP”) server, and receive back a localmobility anchor address (“LMAA”) of a local mobility anchor (“LMA”). TheLMA might serve as the MN's home agent in the Proxy Mobile IPv6 network,and the address of the MN's LMA is thus dynamically assigned.

FIG. 1A provides a high level diagram illustrating a Proxy Mobile IPv6network in an embodiment of the invention. A mobile node (“MN”) 110connects to a Proxy Mobile IPv6 domain 103 through an access point 115.The Proxy Mobile IPv6 domain 103 might interconnect with the Internet107 through a router 155.

The MN 110 might comprise an Internet Protocol (“IP”) host or routerwhose mobility is managed by the network. For example, the MN 110 mightcomprise a laptop computer and/or a transceiver and antenna. The MN 110might operate in IPv4-only mode, IPv6-only mode, or dual IPv4/IPv6 mode.The MN 110 does not have to participate in certain mobility relatedsignaling. Rather, the certain mobility related signaling might beprovided by elements of the Proxy Mobile IPv6 domain 103. The MN 110gains access to the Internet 107 after the MN 110 enters the ProxyMobile IPv6 domain 103 by attaching to an access link through the accesspoint 115.

The access point 115 might comprise a device that allows the mobile node110 to enter the Proxy Mobile IPv6 domain 103. For example, the accesspoint 115 might comprise a WiMAX tower. An access link through theaccess point 115 might be established between the mobile node 110 andone or more elements of the Proxy Mobile IPv6 domain 103 as will beexplained in greater detail.

The Proxy Mobile IPv6 domain 103 might comprise a network or a portionof a network in which mobility is managed by using the Proxy Mobile IPv6protocol. The router 155 might comprise any network routing element thatconnects networks or segments a network. The Internet 107 might compriseanother IP based network or another segment of an IP based network.

FIG. 1B provides a schematic diagram illustrating a Proxy Mobile IPv6network in an embodiment of the invention. The Proxy Mobile IPv6 domain103 comprises at least a mobile access gateway (“MAG”) 120 and at leasta local mobility anchor (“LMA”) 130. The Proxy Mobile IPv6 domain 103might also comprise an Authentication, Authorization and Accounting(“AAA”) server 140 and a Dynamic Host Configuration Protocol (“DHCP”)server 150 in an embodiment. In another embodiment, the AAA server 140and the DHCP server 150 might be considered as residing in the Internet107. The Internet 107 might comprise a Domain Name System (“DNS”) server160 in an embodiment. In another embodiment, the DNS server 160 might beconsidered as residing in the Proxy Mobile IPv6 domain 103.

The MAG 120 might serve as a proxy agent in the Proxy Mobile IPv6 domain103. The MAG 120 manages mobility related signaling for a MN 110 that isattached to an access link of the MAG 120. For example, the MAG 120might be responsible for tracking movements of the MN 110 and forsignaling with the LMA 130. The MAG 120 might be included in a networkapparatus. For example, an access router might include instructionsand/or circuitry to implement functions of the MAG 120.

The LMA 130 might serve as a home agent for the MN 110 in the ProxyMobile TPv6 domain 103. For example, the LMA 130 might serve as ananchor point for home network prefix(es) the MN 110, and the LMA 130might also manage the MN's binding state. As shown, a second MN 110-2might attach to an access link of a second MAG 120-2, and a second LMA130-2 might serve as a home agent of the second MN 110-2 in the ProxyMobile IPv6 domain 103.

The AAA server 140 might comprise a server that implements conceptsincluding one or more of authentication, authorization, and accounting.For example, the AAA server 140 might comprise a Remote AuthenticationDial In User Service (“RADIUS”) server that implements the RADIUSprotocol. Among others, the AAA server 140 might also comprise aDiameter server that implements the Diameter protocol.

The DHCP server 150 might comprise a server that implements the DHCPprotocol. In some embodiments, the DHCP server 150 might comprise aDHCPv6 server that supports DHCP over IPv6. The DNS server 160 mightcomprise a domain server or a subdomain server that implements the DNSprotocol.

FIG. 2 is a flow diagram illustrating methods for supporting mobilitywithout having a mobile node to participate in certain mobility relatedsignaling in an embodiment of the invention. At step 210, the MAG mightreceive an authentication message from the MN. More specifically, the MNmight initiate authentication with the MAG when the MN accesses theProxy Mobile IPv6 domain. The MAG might in turn authenticate the MN withthe AAA server. In some embodiments, in a successful RADIUSAccess-Accept message, a Service-Type attribute is included, and a valueof the Service-Type attribute is set to Framed. In some embodiments, theMAG might also receive the MN's home network information from the AAAserver during authentication. In some embodiments, the AAA server mightcomprise a RADIUS server.

Following successful authentication, the MN's LMA might then bedynamically assigned. More specifically, the MAG might receive from theAAA server in a RADIUS Access-Accept message a local mobility anchoraddress (“LMAA”) of the LMA, and/or Fully Qualified Domain Name (“FQDN”)information of the LMA. The MAG might also receive from the DHCP serverthe LMAA of the LMA.

In some embodiments, the MAG might simply use the LMAA of the LMAreceived in the RADIUS Access-Accept message. Alternatively and/or ifthe LMAA of the LMA is not received, the MAG might receive the FQDNinformation of the LMA in the RADIUS Access-Accept message from the AAAserver at step 220 in other embodiments. The MAG might then perform aDNS lookup of the FQDN information of the LMA for the LMAA of the LMA.Performing the DNS lookup might include sending the FQDN informationfrom the MAG to the DNS server at step 233, and receiving the LMAA ofthe LMA back from the DNS server at step 237.

Alternatively and/or in response to a failure to receive the LMAA backfrom the DNS server by performing the above DNS lookup of the FQDNinformation, the MAG might send a request for the LMAA of the LMA to theDHCP server at step 250 in yet other embodiments. For example, the MAGmight send a DHCP Information-Request message to the DHCP server for theLMAA of the LMA. The DHCP Information-Request message might include theMN's home network information. As noted above, the MN's home networkinformation might have been received by the MAG from the AAA serverduring authentication.

The DHCP server might use the MN's home network information to searchfor the MN's LMA and accordingly the LMAA of the LMA. The MAG might thenreceive a message from the DHCP server and the message might include theLMAA of the LMA at step 255. For example, the MAG might receive a DHCPReply message that includes the LMAA of the LMA. In some embodiments,the DHCP server might comprise a DHCPv6 server.

In some embodiments, the MAG might not be in direct communication withthe DHCP server. In one embodiment, the MAG might in fact communicatemore directly with a DHCP replay agent rather than with the DHCP server.The DHCP relay agent might relay information between the MAG and theDHCP server. In another embodiment, the MAG might perform a DHCP relayfunction by also acting as the DHCP relay agent itself.

In some embodiments, in order to more easily reach the MN at the MN'sdynamically assigned/generated IP address, DNS information of the MNmight need to be updated. For example, another user or another MN mightonly know the MN's FQDN, and need to perform a FQDN lookup in order tofind the MN's current IP address. To better ensure security, it might bedesirable for a node sending a DNS update request to share a securityassociation with the DNS server. However, the MAG might not share asecurity association with the DNS server, and the node sending the DNSupdate request might be the AAA server in some embodiments. Accordingly,the MAG might send the MN's FQDN information and the MN's IP address tothe AAA server, and the AAA server might in turn communication with theDNS server to update the MN's DNS information.

More specifically, the MAG might first send a Proxy Binding Update(“PBU”) message to the MN's LMA at step 260. The PBU message mightinclude a Home Network Prefix (“HNP”) option in a Proxy Mobile IPv6registration message. As noted above, the MN's home network informationmight have been received by the MAG from the AAA server duringauthentication. In some embodiments, if the MAG specifies “0::/0” in theProxy Mobile IPv6 registration message, the LMA will allocate a prefixfor the MN.

At step 263, the MAG might receive a Proxy Binding Acknowledgement(“PBA”) message from the LMA. The PBA message might include prefixinformation that has been confirmed by the LMA for the MN. At step 267,the MAG might receive an address of the MN after a configuration of theaddress. More specifically, the MAG might advertise the prefixinformation through an Internet Control Message Protocol (“ICMP”) RouterAdvertisement message for stateless address auto-configuration.Subsequently, the MN might generate its own interface ID, and formulatean IP address using the interface ID and the advertised prefixinformation. The MN might then send an ICMP Neighbor Solicitationmessage for the MAG to receive the MN's IP address.

After the MAG has receive the MN's IP address, the MAG might send a DNSupdate request message to the AAA server at step 270. The DNS updaterequest message might include the MN's FQDN information and the MN's IPaddress. In some embodiments, the DNS update request message mightcomprise a RADIUS Access-Request message; in the message, theMIP6-DNS-MO attribute might be used for including the MN's FQDNinformation.

At step 272, the AAA server might communication with the DNS server toupdate the MN's DNS information. At step 275, the MAG might receive areply message from the AAA server, and the reply message might include aresult of updating the FQDN information of the MN. In some embodiments,the MAG might receive a RADIUS Access-Accept message; in the message,the MIP6-DNS-MO attribute might be used to provide a result of updatingthe FQDN information of the MN in the Status field.

FIG. 3 is a flow diagram summarizing methods for supporting mobilitywithout having a mobile node to participate in certain mobility relatedsignaling in an embodiment of the invention. At block 310, the MAG mightreceive an authentication message from the MN. Following successfulauthentication, the MN's LMA might then be dynamically assigned. Atblock 320, the MAG might receive FQDN information of the MN's LMA fromthe AAA server. In some embodiments, the AAA server might comprise aRADIUS server. At block 330, the MAG might then perform a DNS lookup ofthe FQDN information of the LMA for the LMAA of the LMA. Performing theDNS lookup might include sending the FQDN information from the MAG tothe DNS server at block 333, and receiving the LMAA of the LMA back fromthe DNS server at block 337.

At block 340, the MAG might determine if the MAG has failed to receivethe LMAA of the LMA after performing the above DNS lookup of the FQDNinformation of the LMA in some embodiments. If so, the MAG might respondby sending a request for the LMAA of the LMA to the DHCP server at block350. In other embodiments, the MAG might send a request for the LMAA ofthe LMA to the DHCP server at block 350 before and/or instead ofreceiving FQDN information and/or LMAA of the LMA from the AAA server.The request might include the MN's home network information. The MN'shome network information might have been received by the MAG from theAAA server during authentication. The DHCP server might use the MN'shome network information to search for the MN's LMA and accordingly theLMAA of the LMA. The MAG might then receive a message from the DHCPserver and the message might include the LMAA of the LMA at block 355.In some embodiments, the DHCP server might comprise a DHCPv6 server. Inother embodiments, the MAG might perform a DHCP relay function when theMAG and the DHCP server are connected through an intermediate networkelement and/or are not connected directly.

At block 360, the MAG might send a Proxy Binding Update (“PBU”) messageto the MN's LMA in some embodiments. At block 363, the MAG might receivea Proxy Binding Acknowledgement (“PBA”) message from the LMA. The PBAmessage might include prefix information that has been confirmed for theMN. At block 367, the MAG might receive an address of the MN after aconfiguration of the address.

After the MAG has received the MN's address, the MAG might send a DNSupdate request message to the AAA server at block 370 in someembodiments. The DNS update request message might include the MN's FQDNinformation. In some embodiments, the DNS update request message mightcomprise a RADIUS Access-Request message; in the message, theMIP6-DNS-MO attribute might be used for including the MN's FQDN. Atblock 375, the MAG might receive a reply message from the AAA server,and the reply message might include a result of updating the FQDNinformation of the MN.

Thus, having described several embodiments, it will be recognized bythose of skill in the art that various modifications, alternativeconstructions, and equivalents may be used without departing from thespirit of the invention. Accordingly, the above description should notbe taken as limiting the scope of the invention, which is defined in thefollowing claims.

1. A method for managing communication in a mobile network, the methodcomprising: sending a request for a local mobility anchor address(“LMAA”) of a local mobility anchor (“LMA”) from a mobile access gateway(“MAG”) to a Dynamic Host Configuration Protocol (“DHCP”) server in aProxy Mobile Internet Protocol Version 6 (“IPv6”) network; and receivingthe LMAA of the LMA from the DHCP server.
 2. The method of claim 1,wherein the DHCP server comprises a DHCPv6 server.
 3. The method ofclaim 1, wherein home network information is included in the request,and the home network information is used by the DHCP server to searchfor the LMAA.
 4. The method of claim 3, wherein the home networkinformation is received from an Authentication, Authorization andAccounting (“AAA”) server during authentication.
 5. The method of claim1, wherein the MAG performs a DHCP relay function when the MAG and theDHCP server are connected through an intermediate network element. 6.The method of claim 1, wherein the MAG sends the request for the LMAA ofthe LMA in response to a failure to receive the LMAA of the LMA from aDomain Name System (“DNS”) server.
 7. A method for managingcommunication in a mobile network, the method comprising: receivingFully Qualified Domain Name (“FQDN”) information of a local mobilityanchor (“LMA”) from an Authentication, Authorization and Accounting(“AAA”) server at a mobile access gateway (“MAG”) in a Proxy MobileInternet Protocol Version 6 (“IPv6”) network; and performing a DomainName System (“DNS”) lookup of the FQDN information of the LMA for alocal mobility anchor address (“LMAA”) of the LMA.
 8. The method ofclaim 7, wherein the AAA server comprises a Remote Authentication DialIn User Service (“RADIUS”) server.
 9. The method of claim 7, furthercomprising receiving an authentication message from a mobile node(“MN”).
 10. The method of claim 7, wherein the FQDN information of theLMA is included in a message after a successful authentication.
 11. Themethod of claim 7, further comprising receiving a Remote AuthenticationDial In User Service (“RADIUS”) Access-Accept message, wherein themessage comprises a Service-Type attribute and a value of theService-Type attribute is set to Framed.
 12. The method of claim 7,wherein performing the DNS lookup comprises: sending the FQDNinformation to a DNS server; and receiving the LMAA from the DNS server.13. A method for managing communication in a mobile network, the methodcomprising: sending a Domain Name System (“DNS”) update request messagefrom a mobile access gateway (“MAG”) in a Proxy Mobile Internet ProtocolVersion 6 (“IPv6”) network to an Authentication, Authorization andAccounting (“AAA”) server, wherein the DNS update request messageincludes Fully Qualified Domain Name (“FQDN”) information of a mobilenode (“MN”); and receiving a reply message from the AAA server, whereinthe reply message includes a result of updating the FQDN information ofthe MN.
 14. The method of claim 13, wherein the DNS update requestcomprises a Remote Authentication Dial In User Service (“RADIUS”)Access-Request message, and the FQDN information is included in aMIP6-DNS-MO attribute.
 15. The method of claim 13, further comprisingsending a Proxy Binding Update (“PBU”) message to a local mobilityanchor (“LMA”); receiving a Proxy Binding Acknowledgement (“PBA”)message with prefix information for the MN; and receiving an address ofthe MN after a configuration of the address of the MN.
 16. The method ofclaim 15, further comprising receiving a local mobility anchor address(“LMAA”) of the LMA from a Dynamic Host Configuration Protocol (“DHCP”)server.
 17. A network apparatus for managing communication in a mobilenetwork and implementing functions of a mobile access gateway (“MAG”) ina Proxy Mobile Internet Protocol Version 6 (“IPv6”) network, the networkapparatus comprising: circuitry adapted to send a request for a localmobility anchor address (“LMAA”) of a local mobility anchor (“LMA”) to aDynamic Host Configuration Protocol (“DHCP”) server; and circuitryadapted to receive the LMAA of the LMA from the DHCP server.
 18. Anetwork apparatus for managing communication in a mobile network andimplementing functions of a mobile access gateway (“MAG”) in a ProxyMobile Internet Protocol Version 6 (“IPv6”) network, the networkapparatus comprising: circuitry adapted to receive Fully QualifiedDomain Name (“FQDN”) information of a local mobility anchor (“LMA”) froman Authentication, Authorization and Accounting (“AAA”) server; andcircuitry adapted to perform a Domain Name System (“DNS”) lookup of theFQDN information of the LMA for a local mobility anchor address (“LMAA”)of the LMA.
 19. A network apparatus for managing communication in amobile network and implementing functions of a mobile access gateway(“MAG”) in a Proxy Mobile Internet Protocol Version 6 (“IPv6”) network,the network apparatus comprising: circuitry adapted to send a DomainName System (“DNS”) update request message to an Authentication,Authorization and Accounting (“AAA”) server, wherein the DNS updaterequest message includes Fully Qualified Domain Name (“FQDN”)information of a mobile node (“MN”); and circuitry adapted to receive areply message from the AAA server, wherein the reply message includes aresult of updating the FQDN information of the MN.